Distributor for fluid pressure brake systems



Nov. 1, 1938.

Filed Jan. 12, 1933 L. KAMENAROVIC DISTRIBUTOR FOR FLUID PRESSURE BRAKE SYSTEMS 2 Shets-Sheet 1 E FL? 1 58 a: 5/ :5 r4 at a:

g3 J0\ Q 3 L. KAMENAROVIC 35,007

DISTRIBUTOfi FOR FLUID PRESSURE'BRAKE SYSTEMS Filed Jan. 12. 1938 2 Sheets-Sheet 2 FL? .5 v

Patented Nov. 1, 1938 PATENT OFFICE 2,135,007 DISTRIBUTOR FOR FLUID PRESSURE BRAKE SYSTEMS Leone Kamenarovi, Milan, Italy, assignor to Fabbrlca Italiana Magneti Marelll Societa Anonima, Milan, Italy, a corporation of Italy Application 13 claims.

This invention relates to an automatic distributor for pressure fluid brakes of vehicles and more particularly for brakes of. vehicles having an auxiliary reservoir for pressure fluid, and said distributor provides for the operation of the vehicle brakes by the fluid of said auxiliary reservoir under the action of the general brake control means and also for the supply of jsaid auxiliary reservoir automatically by a main. reservoir and for automatic application of the vehicle brakes when the supply of pressure fluid from the main reservoir fails through any reason.

' The present invention is particularly useful in connection with brake systems in trailed vehicles in which the auxiliary reservoir is located-on the trailed vehicle when the main reservoir is located on the tractor vehicle; further this invention is adapted for the actuation of. the distributor by means of pressure fluid coming from the brake control conduit of the tractor vehicle.

The present invention also includes an arrangement of the valves controlling the communication of the trailed vehicle'brake cylinders with auxiliary reservoir of. pressure fluid and with outlet as well as an arrangement of the parts actuating said valves for normal and emergency actuations of the brakes, and means for release of the brakes when the trailer vehicle brake system is separated from the main reser- .voir of pressure fluid.

On the annexed drawings:

Figure l is a diagram of the brake system and conduits in a tractor vehicle and in a trailer vehicle, showing the general organization of said -system and the conditions of cooperation of the distributor of. this invention therewith;

Figure 2 is a central longitudinal section of a distributor according to this invention;

Figure 3 is a central longitudinal section of a further embodiment of a distributor according to this invention in part on line 3-3 and in part on line 33' of Fig. 4;

' Figure 4 is a transverse section 'on line 4-4 of Fig. 3.

In the diagram of Fig. 1, 55 denotes the tractor vehicle having a main pressure fluid reservoir 56 supplied by a compressor 51; said vehicle is provided with cylinders 58 whose pistons actuate the brake gears .affixed to its wheels and with conduits 59, 60 by means of which the pressure fluid from said main reservoir is caused to actuate said brake cylinders 58 under the control of a valve 6| actuated by a pedal 62 and connected with said reservoir 56 and conduits 59, 60 by means of tubes 63, 64; the trailer vehicle 65 has January 12, 1938,-Serial No. 184,673 In Italy January 18,1931

brake actuating cylinders 66 energized by pressure fluid supplied by an auxiliary reservoir 61 under the control of.-the distributorof this invention shown at l as connected with the auxiliary reservoir 61 by means of a tube 68 and with the cylinders 66 by means of tubes 69, 16, ll.

Said distributor l is further connected by means of a tube 12 and a coupling 13 with a tube 14 located on the tractor and leading to the'pedal valve 6| for the controlled action of pressure fluid from the main reservoir 56 on said distributor I for the actuation of brake cylinders 66; the

tubes 15 and 16 interconnected by the coupling l to cause pressure fluid from reservoir 61 to energize brake cylinders 66 through 68, l, 69, 10, II; the pressure fluid is restored in auxiliary reservoir 61 from main'reservoir 56 through conduits I6, 15 and under the control of the distributor I.

In the embodiment illustrated in Figure 2, the distributor includes a casing l whose ends are closed by two removable heads 2 and 3, to provide, after one or both said heads are removed,

a free access to members mounted in said casing for adjustments and repairs as may be necessary. The casing I and head 2 confine a chamber 4 which is connected by means of port 5 and tube 69 with the brake cylinders 66 of the trailed vehide; a chamber 6 confined by the casing l and head 3 is connected, by means of. port 1 and tube 68, with the auxiliary reservoir 61 located on th trailed vehicle (Figures 1 and 2).

In the intermediate partition I' of easing I which separates the chambers 4 and 6 from each other, an orifice 8 is provided which is controlled by a valve 9 held in closed-position by the spring l0; said partition has also an aperture ll connected with an outlet l2 opening in the atmosphere under the control of a valve I 3 biased towards open position by a spring l4.

Both valves 9 and I3 are actuated by a rocker l5 having rollers l6 and I1 operative on said valves and mounted on a pivot l6 located in a forked head IQ of a sliding rod l9 which extends partition 9' acts on the box 23 to move the rocker l5 off from valves 9 and I3. The spring is more flexible than spring l0; accordingly when the rocker I5 is moved towards valves l3 and 9 the valve I3 is flrstly closed and thereafter valve 9 opens; on the other hand valve 9 flrstly closes and thereafter valve I 3 opens when said valves are released by rocker It.

The head 2 provides a cylinder 2| in which a piston 20 reciprocates; said piston 20 has a slidable fit on stem l9 and may act by thrust on said stem by means of its face opposite a shoulder IQ of stem I! while the opposite face of said piston is acted on by the pressure fluid entering the cylinder 2| through inlet 22; said inlet 22 is connected with tube 12 and consequently with the pedal actuated valve 6| which, as above stated, controls the supply of pressure fluid to the-brake cylinders of the tractor vehicle and also the actuation of distributor I.

The bottom head 3 provides a cylinder 3| connected by means of a port 32 and tubes l5, 16

with the main reservoir 56 of the tractor vehicle;

a piston 30 is mounted to reciprocate in said cylinder 3| and it confines a chamber 6 therein, said piston 30 being acted on in opposite directions by the pressure fluid operativein chamber 3 on one side and by a spring 29 and main reservoir pressure on the other side.

The piston 30 has a central aperture 23 controlled by a valve 21 which is biased by a spring 26 into its position to close the aperture 28.

Further said piston 33 has-- a projecting collar 25 through which a; stem 26 extends which passes through the partition 9' of the casing i, a tight seal being provided between the parts i and 24 by a gland 53.

The bottom end of the stem 25 on which the spring 26 operative on the valve 27 abuts, is provided with an adjustable collar 33 which is adapted to be engaged by two cross pins 3d fast in the collar 25 of the piston 30 when a downward motion of the piston 3-occurs; the

top end of stem 25 provides a head 12 5' adapted. to engage a bottom flange 23' of box 23 fast with stem l9, W at the time said'stem ,24 is moved downwardly.

.Assuming the parts of the device to be in their operative position'shown in Figure 2 the pressure fluid supplied through I5, it and inlet 32 from the main reservoir 56 into the cylinder 38 opens the valve 21 and enters chamber 6 to go through I and 68 to the auxiliary reservoir 61 located on the trailed vehicle. Owing to the balance of pressures which then exists in the chamber 3 and cylinder .3l when the valve 27 is open, the piston 30ireniains in its inoperative position under the action of spring 29, as illustrated.-

When the operator causes the brakes of the tractor vehicle to be applied by the actuation of the pedal valve 6| the pressure operative in the conduit I5, 13 leading to the cylinder 3! remains unchanged and accordingly the piston 30 does not move, while the control pressure 'fluid supplied from the conduits 14 and-12 and port 22 is operative in the cylinder 2| and on the top face of piston 20 which then moves down and acts by thrust on the stem l9, l3 shifting it downwardly against the action of spring 35; then the rocker l5 and the valves 3 and I3 are operated the valve l3 ,being first closed and the valve 9 being subsequently opened while the stem 24 is left stationary on account of lost motionprovided intermediate its head 24' and the surface of the box 23 opposite thereto, the above described operation of valves l3 and 9 being provided for by respective 'resiliencies of springs l0, l4, as above described. The pressure fluid is thus caused to flow from chamber 6 and auxiliary reservoir 6i connected therewith to brake cylinders 66 of the trailed vehicle through I, 6, 8, 4, 5,39, 10,15.

The controlled actuation of the brakes of the trailed vehicle is thus obtained, the supply of pressure fluid to said brake cylinders being proportional to the stroke of piston 20 under the action of the control pressure fluid caused to act thereon in opposition to spring 35 and pressure operative in chamber 4 and therefore with the pressure made operative on said piston 20 by the control valve 6| of the tractor vehicle; the possible leakages in the conduits and devices located on the trailed vehicle are compensated for by a larger rate of opening of valve 9 as occurring in such circumstances under the pressure operative in the cylinder 2! in view of the lower pressure in chamber 4.

When the control valve 6! is actuated to release the brakes, the pressure falls down in the cylinder 2i and accordingly the piston 20 moves back with stem l9, l9 and rocker l5 under the action of spring 35 to permit the valve 3 to close and valve l3 to open; the brakes of the trailed vehicles are thus released owing to the escape of pressure fluid from brake cylinders 66 through conduits H, 713, 69, port 5, chamber 4, port It and outlet 02.

Should the trailed vehicle system become separated from the tractor vehicle one by efiect of the disconnection of coupling it or generally should the fluid pressure fail within cylinder 3!, such emergency requiring the brakes of the trailed vehicle to be automatically applied to a full extent and be held applied, the valve 2?! closes under the action of its spring 28; then the pressure existing in chamber 3 connected with the auxiliary reservoir ,6! on the trailed vehicle and acting on the piston 30 predominates on the spring 29 and causes the piston 30 to move down and to shift the stem 24 therewith by means of the pins 34 of its collar 25 engaging the collar 33; then the head 24' of the stem 2 3 engages the flange 23' of the box 23 fast with the stem 09, it and depresses the spring 35 to carry said stem up to the bottom end of its own stroke the stem 99 being free from the piston 20 in the contemplated direction of motion.

Then the rocker I5 and valves l3 and 9 operate in the described manner to cause the full actuation of the brake cylinders 66 of the trailer vehicle under the action of the fluid contained in the auxiliary reservoir 61; the trailer brakes are thereafter held applied until the pressure is restored in the cylinder 3I'and the piston 30 is permitted to move up to provide for the return motion of the stem l9, IS with rocker l5 under the action of spring 35.

The hereinafter described embodiment shown in Figures 3 and 4 provides a compact and efiicient arrangement of the valves 9 and I3 intended to control the communication of the brake cylinders 66 of the trailed vehicle with the auxiliary reservoir 61 of pressure fluid located on said vehicle and with the outlet l2; this embodiment also includes another arrangement of the pistons 20 and 30 intended to actuate said' head 2 at one end and an intermediate parti-- tion I" while a head 3 providing a chamber 6' closes'said casing at the opposed end? thereof. The chamber 6' is separated from the space with-v in casing by means of a' partition 3' provided by the head 3 and having an aperture 8 controlled position by a spring "I. v

A piston. 26 is mounted to reciprocate in the casing I intermediate the partitions I" and 3'; said piston 20 includes two sections spaced by a.

ring 52 having apertures therethrough and a cup sleeve 31 is mounted in a central aperture of piston 20 and engaged therein by a screwthreaded collar 36, the side wall of the cup'sleeve 3'! having apertures 38 which communicate. with apertures 5| and the space 39 confined between the two sections of thepiston 20 and hence with outlet port l2 provided in the ,casing I. The mouth of the cup sleeve '31 provides the seat ll of a valve 1 3 connected longitudinally with the valve 9 by means of a coupler 40 which engages the enlarged heads9' and I3 of the two valves 9 and |3. I

A piston 30 is mounted to reciprocate in the chamber 3| defined by the head '2 and the par-- tition of.casing I, and the stem 36 ofsaidpiston provides a longitudinal chamber 4| which is in communication on the one side with the chamber 6" intermediate the piston 30 and the head 2 and on the other side with chamber 3| through ports 42; the chamber 4| provides a seat 4| on which a ball valve 21 is seated by a spring 26 which abuts on the head 2. a

The piston 3|) is loaded by a spring 29 abutting on the stationary partition I" and biasing it in its location adjacent to head 2 with the valve. 21 forced on cooperating seat 4| by the spring 26; the spring l4 abutting on the partition 3' of head 3 holds the piston 20 forced against the. stem 30" of piston 3|] in front thereof, said stem 36' extending with a seal fit through partition I" and being in condition toact on the cup sleeve 31 and piston 20.

The surfaces of valves 9 and I3 adapted to fit on the respective seats are spaced apart through such a distance as when the pistons 36 and 20 are in the locations they are moved into by the action of springs 29 and I4 respectively, the valve 9 is held in closed position by the spring I whilst the.valve,|3 remains spaced from its seat II at the mouth of the cup sleeve 31.

The chamber 6" is connected by a duct 43 with a port I connected with the conduit 68 leading from the auxiliary reservoir 61 of pressure fluid located on the trailer vehicle; the duct 43 also opens in the chamber 6' and causes this chamber to communicate with port I.

The chamber 4 confined between the partition 3 and piston 26 is connected with port 5 from which extends the conduit 69 leading to the brake cylinders 66 of 'the trailed vehicle, while the chamber 2| confined between the piston 20 and partition I" is connected with the port 22 which in turn is connected with the conduit 12,

. 14 leading to the pedal control valve 6| located on the tractor vehicle; the .outlet ports 38,- 5|, 39 of piston 20 are permanently connected with the atmosphere through the outlet ports |2 provided inthe wall of casing The chamber 3| confined between partition I" and piston 30 is connected with the port 32 communicating in turn through conduit 15, 1a with the main reservoir 56 of pressure fluid located on the tractor vehicle; the communication is made through the passage 44 of a shutter 45 adapted to be manipulated by the handle (46 and "forced by a spring 41 towards its seat 48. Said shutter munication of chamber 3| with port 32 is closed..

When the device is in its inoperative conditions illustrated in Fig. 3, the pressure fluid supplied by the main reservoir 56 of the tractor vehicle enters the port 32 and chamber 3| and opens the valve 21 against the'action of spring 26; then it flows into chamber 6" and goes to auxiliary reservoir 61 located on the trailed vehicle through duct 43 and port I; the pressures in chambers 3| and 6" balance each other and consequently the piston 30 holds its inoperative position under the action of spring 29.

At the time the brakes are applied by the actuation of the pedal control valve 6| located on.

the tractor vehicle, the pressures acting in opposite directions on piston 30 are balanced and said pistonis stationary. Under the action of the control pressure-fluid fed into chamber 2| through 14, 12, 22, thepiston 20 moves against the action of its spring] I 4 andthen' firstly the valve |3 is seated on its seat II to shut the com munication of port 5 and ,brake'cylinders 66 of the trailed vehicle with atmosphere and subsequently the action developed by piston 2|] and cup sleeve- 31 on the coupled valves l3 and 9 Ccauses the valve 9 to open while holding the valve |3 closed.' Thus the pressure fluid flows from auxiliary reservoir 6'| to the brake cylinders 66 through I, 6', 8, 4,5, 69, III, II. In the above stated conditions the brakes are applied with a controlled pressure because the stroke of thepiston 2|] and therefore the rate of opening of valve 9 are proportional with the pressure caused to act in cylinder 2| by the con-' trol valve 6| and the possible fluid leakages in the brake system of the trailed vehicle are compensated for by a larger degree of opening of the valve 9,

When the control valve 6| .is operated for the the valve '|3 coupled with it by coupler 40 to move furthencauses the seat ||to be opened to put' the port 5 in communication with the atmosphere through 4, 38, 5|, 39 and outlet l2.

In the event. the trailed vehicle is separated from the tractor, the chamber 3| freely communicates with atmosphere through 44 and ,32; then ,the fluid supplied by theauxiliary reservoir 61 and operative in-6" through port I and duct 43- causes the valve 21 to close and, then moves the piston 30 against the action of spring 29;

the stem 30 thus acts on the piston 20 to close valve l3 and open valve 9 and causes the trailed vehicle brakes to be fully applied under the action of pressure fluid supplied through valve 9 by the auxiliary reservoir 61 of" said vehicle.

When, assuming the pa'rts tobe in the lastly described conditions, it is necessary to release the brakes of the trailed vehicle, the shutter 45 is manipulated by means of its handle 45 to close the passage 44 and carry the passage 49 in a position connecting the chamber 3| with the duct 43 and accordingly with chamber 65' and port 1 connected with the auxiliary reservoir 61.

Then pressures in chambersi" and 3| balance each other and the piston 3|! is restored, by the spring 29 in the illustrated position to permit the piston 20 to take under the action of the spring l4 its position by which the valve 9 cuts the intercommunication of port with port 1 and the valve l3 opens to connect said port 5 with the outlet l2 opening to the atmosphere.

By manipulating the shutter 45 to restore it in its position illustrated in Figures 3 and 4, the firstly described conditions are again obtained and then the brakes are again applied and held applied by the pressure fluid derived from the auxiliary reservoir 61.

The'above described manipulations of the shutter 45 may be repeated if necesary, until the pressure fluid stored in the auxiliary reservoir 61 is exhausted.

The embodiment of the shutter 45 in the distributor l removes troubles and leakages inherent to devices in which an equivalent valve is located at adistance from said distributor and is connected with it and pressure fluid reservoir 61 by means of separate conduits.

The distributor of this invention provides for the desired control of the brakes in a trailed vehicle under any circumstance and its arrangement and organization make the inspection and adjustment of its parts easy by the mere removal of the casing heads without disconnecting the conduits leading to said casing.

I claim:

1. A distributor for controlling the intercommunication of a main pressure fluid reservoir, an auxiliary reservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a casing, means in said casing providing two intercommunicating chambers the flrst one having a connection with said auxiliary reser- 'voir and the second one having a connection with said brake cylinders and an outlet, valve means controlling the intercommunication of said chambers and said outlet, means actuated by said control pressure fluid for operating said valve means, a head on said casing providing a cylinder whose mouth opens in said first chamber and whose end has a connection with said main reservoir, a pistonmounted to move in said cylinder intermediate said mouth and end thereof, and lost motion means for actuation of said valve means by said piston.

2. A distributor for controlling the intercommunication of a main pressure fluid reservoir, an auxiliary reservoir, a control pressure fluid source and brake actuating cylindersin a. vehicle, comprising a casing, means in said casing providing two intercommunicating chambers the first one having a connection with said. auxiliary reservoir and the second one having a connection withsaid brake cylinders and an outlet, valve means controlling the intercommunication of said chambers and said outlet, means actuated by said control pressure fluid for operating said valve means, a head on said casing providing a cylinder whose mouth opens in said first chamber and whose end has a connection with said main reservoir, a piston mounted to move in said cylinder intermediate said mouth and end thereof, said piston having a port, a valve controlling said piston port, means tending to 'close said piston port valve against said main auxiliary pressure operative in said cylinder and lost motion means for actuation of said valve means by said piston.

'3. A distributor for controlling the intercommunication of a main pressure fluid reservoir, an auxiliary reservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a casing, meansin said casing providing two intercom'municatlng' chambers the first one having a connection with said auxiliary reservoir and the second ,one having a connection with said brake cylinders and an outlet, a valve controlling said portand a valve controlling said outlet, sprlng'm'eans holding said port valve closed and said outlet valve open, a rocker actuating said outlet valveand said port valve in succession, means actuated by said control pressure fluid for operating said rocker, a return spring for said rocker, a head on said casing providing a cylinder whose mouth opens in said first chamber and whose-end has a connection with said main reservoir, a piston mounted to move in said cylinder intermediate said mouth and end thereof, and

.lost motion means for actuation of said rocker by said piston when the main pressure fluid fails in said cylinder.

4. A distributor for controlling the intercommunication'of a main pressure fluid reservoir, an

auxiliary reservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a casing, means in said casing providing twointercommunicatlng chambers the first one having a connection with said auxiliary reservoir and the second one having a connection with said brake cylinders and an outlet, valve means controlling -the intercommunication of said cham bers and said outlet, ahead on said casing providing a cylinder having a connection with said control pressure fluid source, a piston mounted to move in said cylinder under said control pressure made operative therein, a member acted on by said piston and actuating said valve means,

return means for said member and actuating piston, a second head on said casing providing a cylinder whose mouth opens in said first chamber and whose end has a connection with said main reservoir, a piston mounted to move in the last named cylinder intermediate said mouth and end thereof, and lost motion means for actuation of said valve means actuating member by said last named piston.

5. A distributor for controlling the intercommunication of a main pressure fluid reservoir, an auxiliary reservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a casing, means in said casing providing two intercommunicating chambers the first one having a connection with said auxiliary reservoir and the second one having a connec-' tion with said brake cylinders and an outlet, a valve controlling said port and a valve controlling said outlet, spring means holding said port valve closed and said outlet valve open, a rocker actuating said outlet valve and said port valve in succession, a head on said casing providing a cylinder having a connection with said control reservoir, a piston mounted to move in the last named cylinder intermediate said mouth and end thereof and. adjustable lost motion means for actuation of said rocker actuating member by said last named piston. i

6. A distributor for controlling the intercommunication or a main pressure fluid reservoir, an

auxiliary reservoir, a control pressure fluid sourcev and brakeactuating cylinders in a vehicle, comprising a casing, apartition in said casinghaving a port and providing two chambers intercommunicating with said port the first one havin a connection with said auxiliary reservoir and the second one having a connection with said brake cylinders and an outlet, valve means con trolling said port and outlet, a removable head on said casing confining said second chamber and-having a connection with said control pressure source, a piston mounted to move in said cylinder under said control pressure fluid made operative therein, a member mounted-to reciprocate throughsaid partition and acted on by said piston to actuate said valve means, return means for said member operative between said member and partition, 9. second removable head on said casing confining said first named chamber and providing a cylinder having a connection with said main reservoir, a piston mounted to move in the last named cylinder and acted on by the auxiliary reservoir pressure and main reservoir pressure. in opposition to each other,

and lost motion means for actuation of said member, by said last named piston.

7. A distributor for controlling theintercommunication of a main pressure reservoir, an auxiliary reservoir, a controlpressure fluid source and brake actuating cylinders in a vehicle, comprising a casing,- a partition having a port and 1 separating two chambers in said .casing said chambers intercommunicating through a port in said partition and one of them having a connection with said auxiliary reservoir and the second one having a connection with said brake cylinders, a piston mounted to move in an apertured space of said casing to confine said second chamber and having an outlet, a 'valve controlling said port and a valve controlling said outlet said valves being aligned and interconnected, spring means holding said port. valve closed and said piston spaced from said outlet valve, means for causing said control pressure fluid to act on said piston agalnst'the action of said springs, a second piston mounted to move in a space of said casing, means causing pressure fluid from said auxiliary reservoir, and pressure fluid from said main reservoir to act on said second piston in opposition to each other, and a stem fast on said second piston and operative by thrust on said first piston to'move said piston against said spring means to close said outlet and open said port when the auxiliary reservoir pressure predominates on said second piston.

8. A distributor for controlling the intercommunication of a main pressure reservoir, ,an auxiliary reservoir, 8, control pressure fluid source brake actuating cylinders in a vehicle, comprising a casing, a partition separating two cham-.

.? ,b rs in'said casing said chambers intercommuni- ,cating througha port in said partition and one them hay la connection with said auxiliary eservoir and the second one having a connectionwitn said brake cylinders, a piston mounted to movers an apertured space of said casing to confine second chamber and having a recess and casing apertured space, a valve controlling said port and a valve controlling the mouth of said piston recess .in said second chamber said valves being aligned and interconnected, spring means holding said port valve closed and said piston spaced from said outlet valve, means for causing said control pressure fluid to move said piston against the action oi said springs, a member mounted to move in a space of said ca ing, means causing pressure fluid fromsaid auxiliary reservoir and pressure fluid from said main reservoir to act on said movable member in opposition to each other and single direction operative means on said member to move said piston against said spring means to close said outlet and open said port when the auxiliary reservoir pressure predominates on said movable member. 9. A distributor for controlling the intercommunication of a main pressure-reservoir, an auxiliaryreservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a. casing, a partition having a port and. separating two chambers in said casing said chambers intercommunicating through a; portin said partition and one of them having a connection with said, auxiliary reservoir and the second one having a connection with said brake cylinders, apistorn mounted 'to move in an apertured reservoir and pressure fluid from said main reservoir to act on said second piston in opposition to each other, said piston having an aperture for the flow of pressure fluid-from said main res.- ervoir to said auxiliary reservoir, a return valve controlling said piston aperture, and a stem fast 1 on said second piston and operative by thrust on means causing pressure fluid from said auxiliary said first piston to move said piston against said spring means to close said outlet and open said port when the auxiliary reservoir pressure predominates on said second piston.

10. A distributor for controlling the intercom- ,munication of a main pressure fluid reservoir,

an auxiliary reservoir, a control pressure-fluid source and brake actuating cylinders in a vehicle, comprising a casing, means separating two inter communicating chambers in said casing one of u said chambers having a connection with said "auxiliary reservoir and the second chamber having a connection with said brake cylinders and an outlet, valve means controlling the intercommunication of said chambers and said outlet, means actuated by said control pressure fluid for operating said valve means, a member mounted to move in a chamber of said casing, a connection for supplying pressure fluid from said auxiliary reservoir into the space at one side of said movable member, a-connection for supplying pressure fluid from said main reservoir into thespace on the opposite side of said movable movable member.

11. A distributor for controlling the intercommunication of a mainpressure fluid reservoir, an auxiliary reservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a casing having two end chambers and an intermediate chamber separated from each other by partitions having ports therein, one of said end chambers having a connection with said auxiliary reservoir and the adjacent intermediate chamber having a connection with said brake cylinders and an outlet in its intermediate portion, a valve controllingthe port of said partition between said end and intermediate chambers, a spring holding said valve closed, a piston movable in said intermediate chamber and having an orifice leading to said outlet, a valve controlling said orifice and interconnected with said first named valve, a spring acting on said piston to hold it spaced from said valve controlling said orifice therein, said-intermediate chamber having a connection with said ,control pressure fluid source for causing said control pressure fluid to actuate said piston in opposition to said spring operative thereon, a second piston mounted to reciprocatein the other one of said end chambers, a member seal-extending from said second piston through said partition" separating said intermediate chamber from said second named end chamberior actuating said first named piston, said second named end chamber having connections with said main reservoir and auxiliary reservoir at the opposite sides of said second piston therein, said second piston having an aperture for the flow of pressure fluid from said main reservoir" into said auxiliary reservoir and a return valve controlling said aperture of said second piston. v

12. A distributor for controlling the intercommunication of a main pressure fluid reservoir, an auxiliary reservoir, a control pressure fluid source and brake actuating cylinders in a vehicle, comprising a casing having two end chambers and an intermediate chamber separated from each other by partitions having ports therein, one of saidend chambers having a connection with said auxiliary reservoir and the adjacent intermediate chamber having a connection with said brake cylinders and an outlet in its intermediate portion, a valve controlling the port of said partition between said end and intermediate chambers, a spring holding said valve closed, a piston movable in said intermediate chamber and having an orifice leading to said outlet, a valve controlling saidorifice and interconnected with said first named valve, a spring acting on said piston to hold it spaced from said valve controlling said orifice therein, said intermediate chamber having a connection with said control pressure fluid source for causing said control pressure fluid to actuate said piston in opposition to. said spring operative thereon, a second piston mounted to reciprocate in the other one of said end chambers, a member seal-extending from said second piston through said partition separating said intermediate chamber from said second named end chamber for actuating said first named piston, said second piston providing twoture for the flow of pressurefluid from said main,

reservoir into said auxiliary reservoir and a return valve controlling said aperture of said second piston.

13. A distributor for 'controlling the intercommunication of a main pressure fluid reservoir, an auxiliary reservoir, 'a control. pressure fluid source-and brake actuating cylinders in'a vehicle, comprising a casing having two end chambers and anintermediate chamber' separated from each other by partitions having pqrts therein, one of 'said end chambers having connection with said auxiliary reservoir and e' adjacent intermediate chamber having a connection with said brake cylinders and an outlet in its intermediate portion, a valve controlling the port of said partition between said end and intermediate chambers, a spring holding said valve closed, a piston movable in saidintermediate chamber and having an orifice leading to said outlet, a valve controlling said orifice and interconnected with said first named valve, a spring acting on said piston to hold it spaced from said valve controlling said orifice therein, said intermediate chamber having a connection with said control pressure fluid source for causing said control pressure fluid to actuate said piston in opposition to having connections with said main reservoir and.

auxiliary reservoir at the opposite sides of said second piston therein, said second piston having an aperture for the flow of pressure fluid from said main reservoir into. said auxiliary reservoir and. a return valve controlling said aperture of said second piston, all said connections being provided in said casing and the ends of said casing consisting of removable parts.

LEONE KAMENAROVIC. 

